In some people the upper and lower jaws do not grow in proportion to their face, or in proportion to each other.  Unbalanced growth means that the upper or lower jaws can be too large, too small, asymmetrical or abnormally shaped. This can result in problems with the bite, (malocclusion), functional problems with chewing and tooth-wear, and in an unbalanced facial appearance.  Many of these conditions can be corrected by surgery on the jaws.